Control system for elevators



May 17, 1932. H. w. WILLIAMS CONTROL SYSTEM FOR ELEVATORS Filed May 27, 1929 Patented May 17, 1932 HAROLD W. VIILLIAMS, OF WILKINSBURG,

PENNSYLVANIA, ASSIG'NOR TO 'NESTENG- I-IOUSEElLECTRIC 8c 'MANUFACTURING COMPANY, .5L CORPORLTION OF ENNSYL- VANIA CONTROL SYSTEM FOR- ELEVATORS Application led May 27,

My invention relates to control systems for motors and has particular relation to systems of control for hoists and elevators.

Aanother object of my invention is to provide a system for elevators operating at worling speed within a local zone of operation and at an increased speed in another or express zone of operation, wherein temporary exit and re-entry of the car from and to the local zone will insure the operation of the car at the working speed.

Another object ofmy invention is to provide a control system for elevators adapted to operate at express and local speeds in order that the predetermined operation shall be. effected even under slightly abnormal conditions.

My invention is particularly applicable to control systems for elevators adapted to operate in local and in express zones and in which the operator may so control the system as to defeat the desired object and comprises an additional inductor plate properly located in a hatchway in order to ens ure the change from express speed to local speed.

My invention will be described in combination with the accompanying drawings wherein Figure l is a diagrammatic view of a bank of elevators serving a plurality of floors, 14C in number, and showing the relative positioningr of the express and local zones; and

Fig. 2 is a diagrammatic view of thecontrol system for an elevator embodying my invention, as applied to a simplified form of speed-control system.

In Fig. l are shown three eleva-tor hatchways, indicated as A, B and G, in which eleindicated as A', B" and C, respecoperate in the usual manner. The cars ctively suspended by means of cables from them' over hoisting drums y and C, respectively, to counterweights ii", B5 and C". A. ua ir of inductor irons are normally po- 'n each of the hatchways, these inir irr ns defining the point between. the localand the Tpress zones. For example, in the hat/hway 'lnductor iron 15 is indicated tly above the second-floor Q. es

as positioned 1929. Serial N0. 366,278.

level and on the left-hand side of the hatchway. A similar inductor iron 16 is shown as located slightly below the fourth-floor level upon the rightehand side of the shaft. lVith this arrangement, we may assume that the elevator A is to operate to give express service; that is, to stop at none of the floors between the first and fourth floors and there after to proceed as a local elevator .from the fourth tothe fourteenth licor; that is, the car will make all necessary stops between the fourth and the fourteenth floors in response to the usual passenger-operated signal devices ordinarily provided in elevator-control systems. By similar arrangement of inductor irons 17 and 18 in the hatchway B, the elevator therein may be operated as an er press elevator to the ninth floor and as a local elevator for the remaining floors, while the car in the hatchway C may give lo-cal service to the rst eight floors and express service from. the ninth floor to the upper terminal.

This express and local operation is usual in very tall buildings in order to prevent the trai'lic to or from a given section of the building from crowding the traffic to or from a different section of the building. As may readily be seen, should the elevator A', for example, start from the first Hoor and make all of the stops at floors between the first and fourteenth, the capacity of the elevator would have to be very great in order to provide room on the car to take on the passengers at the twelfth or thirteenth floors. Similarly, on a down`trip, the condition of stopping at all of the floors would cause the car to be so crowded, as it approached the few lower floors, that there would be no room for additional passengers from these floors to be cared for by this car. This local and express system of operating elevators is quite usual in present day buildings of more than ten stories in height.v

A system of this kind is disclosed and claimed in application, Serial No. 197,830, tiled June* l0, 1927. by F. E. Lewis and assigned to the VVesting-liouse Electric & Manufacturing Company, now Patent No. 1,793,497, Feb. 24, 1931.

Fig. 2 illustrates a diagram of connections of a control system with which the particular device embodying my invention is employed. An elevator car C is suspended by means of a cable CA which passes over a hoisting drum D to a suitable counterweight CW. The hoisting drum D may be driven in any suitable manner and, in the. illustrated embodiment, the driving means comprises a motor-generator-motor set of the Ward- Leonard type. This set comprises a driving motor M provided with a shunt field winding MF and having its armature M directly c0upled to the armature G of a generator G. The generator G is of the compoundwound type and comprises an armature G', a series field winding GSF, a separately excited field winding GF and a demagnetizing field winding GAF. The armature G of the generator G is connected in loop circuit with the armature EM of an elevator-hoisting motor EM. The elevator motor EM is provided with a separately excited field winding EMF and has its armature EM directly coupled to the hoisting drum. The direction and speed of the hoisting motor EM is controlled in any suitable manner, as by controlling the direction and amount of current through the field winding GF of the generator G.

The control elements include an updirection switch 1, and a d0wndirection switch 2 which are effective, when properly energized, to selectively connect the generator field winding GF to line conductors L1 and L2, with the current passing therethrough in opposite directions. The speed of the motor EM is varied by the inclusion or exclusion of a resistor R selectively controlled by a speed relay 3. Various direction and speed relays may be controlled from the elevator car C by means of a car switch CS, for example, a plurality of slowdown and stop inductor relays 6, 7, 8, 9 and 11, and a. pair of electromagnetic relays 4 and 5. The connections between the various relays and switch es will be hereinafter described in connection with an assumed operation of the elevator.

Let it be assumed that it is desired to more a car, for example, the car A upwardly. The operator moves the handle of the car switch CS to the right to energize the updirection switch 1 by way of a circuit which extends from line conductor L1, through conductors 22 and 23, Contact 24, sector 25 of car switch CS, contact member 26, conductor 27, the coil of updirection switch 1 and the conductor 28, to line conductor L2, Updirection switch 1, when actuated, energizes the field winding GF with current in one direction by way of a circuit extending from line conductor L1, through conductors 29 and 31, contact members b on updirection switch 1, conductor 32, field winding GF, conductors 33 and 34, contact members c on updirection switch 1, conductor 36, resistors R and R and conductor 38, to line conductor L2. This energization of the generator field winding GF causes the generator G to supply the hoisting motor EM with voltage in one direction and the car starts upwardly.

The updirection switch 1 also completes a self-holding circuit which extends from line conductor L1, through conductors 22 and 42, the normally closed contact members controlled by inductor relay 7, conductors 4l and 39, contact members a on updirection switch 1, the coil of updirection switch l and conductor 28, to line conductor L2. The elevator car, thus started, continues to 0perate at a predetermined and relatively slow speed.

If the operator desires to cause the car to move upwardly at a higher speed, he moves the handle of the car switch CS farther to the right to effect engagement of the contact sector 25 with the fixed contact member 43. rlhis operation establishes a circuit for energizing the speed relay 3 which may be traced as follows from line conductor L1, through conductors 22 and 23, contact niembers 24, 25 and 43 on car switch CS, conductors 44 and 46, the coil of speed relay 3 and conductor 47, to line conductor L2. The actuation of speed relay 3 closes its contact members a to shunt the resistor R` from the circuit of the generator field windingr GF by way of conductors 49, 52 and 51, with the result that the motor operates at a higher speed. This speed, which is hereinafter referred to as the high speed, is intended to be the highest speed which the elevator will attain while in a local zone.

The speed rela-y 3 completes a self-l1olding circuit which extends from line conductor L1,'through conductors 22 and 56, the contact members of down-slow-dowil-inductor relay 8, conductor 54, the contact members of upslowdown inductor relay 6, conductor 53, contact members b on speed relay 3, conductor 46, the coil of speed relay 3 and conductor 47, to line conductor L2. y

Itis, therefore, seen that the motor will be maintained in operation at its high speed Y until the slow-down inductor relay 6 has been operated by coming into cooperative relation with a slow-down inductor plate SU, (F 2) one of which is mounted adjacentto each of the fioors at which the elevator to stop. An inductor plate SD for each floor, suitably disposed with respect thereto, is also provided for entering into cooperative relation with down slow-down inductor relay 8 and effecting the operation thereof to initiate the stopping of the car at a selected floor when the car is descending. An inductor plate S for each fioor is provided for entering into cooperative relation with stopping inductor relay 7 to effectthe final stopnea-:58,283

ping ofthe elevator car. The coils of the inlcliuctor relays 6, 7 .and Snare energized to render the relays operable only when the car switch has been returned to normal position, because vthe circuits for these coils include a contact 6C)v on the car switch CS that is closed only when the car switch is in olli position.

ln series with the generator ield winding GF and, therefore, in series-circuit relation toresist-or R, is connected a second resistor R which may be excluded lirom this circuit by the operation of the relay 5. Vl`he function of this resistor R is to maintain the speed oit the motorat the high-speed condition herein before mentioned, and it is desired to clude this resistor when the car passes into the high-speed zone, thereupon causing the motor to operatev at express speed or at a speed above the usual liigh speed. l the high speed of the elevator be 60() feet per minute, thev express speed may be considerably in excess of vthat speed, for example, 750 to 900 feet per minute, but it is to be understood that these values are illustrative and that the expressspeed may be any value wit-hin the well known safety limits,

The relayy 5 is energized through the agency of a pair ofinductor relays 9 and l1 in combinationl with a relay 4c, certain contact members of the relay l being electrically connected in series with the coil of relay 5. Theoperation of relays 9, ll, l and 5 may be best described with reference to an assumed. cycle of operation. Assume the conditions of operation described for the elevatorcar A with reference to Fig. l, the elevator may be started from the first floor by a movement of thecar switch CS and the consequent operation of the control system previously described, and the car will move upwardly on its first trip at high working speed. When the car arrives at the fourteenth floor and ris reversed for the down trip, the Amovement of the car switch CS, to the left, closes a circuit for the coil of inductor relay l1 which may be traced as ollows:-from line conductor Ll, through conductors 22 and 6l, the coil of relay ll, conductor 82, one set of contacts of a doublepol-e switch l2y mountedv in the car C. conductor 83, contact members e on dow-ir. rection switch 2 and conductors 65, S5 and 28, to lineconductor L2. Until the indue-tor relay ll passes the down inductor iron (in this case slightly below the fourth level) this relay is ineffective to control ny operation of the motor. rhe car will. th-me fore, proceed as local elevator, that is, at speeds not greater than high speed, from the fourteenth to the fourth floors, mal* necessary stops in response to passenge erated signals. As the car leaves` the floor, the relay l1 passes the industor 16, and the relay is actuated. close contact members, thus completing a circu t to actuate relay l wiich extends from line conductor Ll, th ough conductors 22, 6l and 59, the contact members of relay ll, conductor 58a., the contact members of relay 9, conductor 58, the coil of relay l and a part of conduct-or el' 'to line conductor L2. relay l closes its Contact members a, thereby energizing the coil of relay 5 through a circuit which may be traced as 'iollowsz From line conductor lil, through conductor 7l, the coil cf 5, conductor (33, contact members a on relay and conductor T2, to line conductor L2. Relay 5, ".vhen energized, closes its contact members and shunts or short-circuits resistor R Ythrougl'i the conductors 5l, 52 and Exclusion of resistor R from the circuit el the i field winding` GF increases the speed to the abnormal or express speed, and the cui will travel at this express speed 'go *l ai.; iile'b licor. Suitable limit switches are fjn'ovidef to cause the car to stop at the first door, ano these limit switches generally opera f in elevator systems, to stop the car at limits of travel. lt is not thought neces.. to illustrate them here.

The relay el, einen actuated, closes a seltholding circuit extending from line con-duw tor Ll, through conductor 7l and 5T, contact members c on relay e, conductors T-l and 8a, the contact members or un inductor `r- 5 the coil of relay and av 9, conductor )art of conductor el?, to line conductor lil/Yhen the ar is again started upwardly, the relay l remains energized, since the only point at which the circuit 'tor this relay muy be broken is at the normally closed Contact members of relay 9 and, therefore, the car accelerates to and moves at express speed until it arrives at the third Yfloor. is the car passes the second floor, 'the inductor iron l5, cooperating with the relay 9, causes` this relay to open its contact members and de- Tf() energize the relay and, coi'isequen-tljg, the relay 5.

at al The coil of relay 9 is energized i times during which the relay l remains closed and the updirection switch l is energized.

he circuit for this coil extends from line conductor Ll, through conductors 22, (3l and T6, the coil of relay 9, conductor 2"?, the other set o contact members of the double-pole switch l2 on the car, conductor T8, contact members?) orp reLay Ll, conductors 69 and 79, Contact members c of switch l, and coi-idrictors 67, ('36 and 28, to line conductor L2. The operation o relay 9, therefore, de-energiz/,es relay el and opens Jhe circuit excluding resistor R, and 'the csr operate, from the fourth to the 'fourteenth floor at speeds not Y than high speed.

lt frequently happens that, when a car is descending and arrives at t ie junction between the local and express Zones., the attendant finds it necessary to re-enter the local vio ' will be initiated Zone to serve the floors which may have been accidentally missed when the car was initially descending. Assuming that the attendant had moved the car out of the local zone to such an extent as to have caused actuation of inductor relay 1l, the conditions of operation new existing would be such that 'the ca r would operate at express speed so that, upon re-entry of the car into the local Zone, the car would be travelling at such high speed as to make it extremely diflicult to stop the car level with any of the floors in that Zone.

It will be observed that the inductor irons or plates for actuating inductor relay 9 to reduce the speed of the car from express speed to hiofh speed must be placed somewhat in advance of the boundary between the express zone and the local Zone, in order that sufficient time may be given to permit the car to slow down from express speed to high speed and to be brought to rest at the first floor in the local zone, should service be desired at this floor. This advance distance may be several floors. F or example, the inductor plate l5 for the car in hatchway A will be approximately at the second floor level so that reduction in speed of the car just after the car passes the second-floor level. This arrangement will allow suiiicient time for the car to reduce its speed from, say 900 feet per minute, to 600 feet per minute, before the car approaches that point in advance of the fourth floor at which relays G and 7 must be actuated to bring the car to a stop at the fourth-floor level.

On the other hand, when the car is descending, it is necessary that inductor relay 11 shall operate just after the car passes the fourth-floor level, so that the car may then operate at express speed to the first fioor. Hence, inductor plate 16, cooperating with inductor relay 11, must be mounted just below the fourth-floor level.

It frequently happens, however, that the attendant on a car discovers that a call for service in the local zone has been accidentally missed and that it is necessary to reverse the operation of theV car to serve such call. If the car has passed inductor plate 16 before such reversal occurs, it will be seen that the re-entry of the car into the local zone will be at such time as the car is operating Linder express-speed conditions, so that, even though it is desired to give service at the floors witnin the local Zone, the car is operating at such high speed that it cannot be stopped accurately at the floors, and particularly, it cannot be accurately stopped by the automatic landing devices, such as inductor relays 6 and 7.

For this reason, I have provided an additional inductor plate 15 mounted at a point approximately level with the fourth floor so that, if the car is reversed at any point between inductor plates 1G and l5, the rfi-entry of the car into the local zone will cause in ductor plate l5 to actuate inductor relay 9 to thereby reduce the speed of the car to high speed.

It has been found extremely desirable that such arrangement be used particularly when the express speed is of a relatively high value. By this construction, it is insured that the car will operate at speeds not greater than high speed in the local zone under all conditions of operation.

The device more particularly embodying my invention thus provides an additional safeguard cooperating with one of a plurality of relays to ensure that proper speed shall be maintained in a local zone if, for any reason, the operator has moved the car past the dividing line between the two zones, and the relay normally provided to ensure a change in the speed does not happen to operate.

The apparatus disclosed is merely illustrative, and I do not desire to be limited to the specific details shown, except as defined in the appended claims.

I claim as my invention:

l. In a control system for elevators, an elevator car operable in a hatchway past a plurality of fioors, motive means for said car, means for controlling said motive means to cause said car to run at a plurality of different speeds, means defining a plurality of zones of operation for said car, each zone including a plurality of adjacent fioors, said zone defining means including means operable by movement of said car in one direction within one predetermined distance of the boundary between two of said zones for actuating said control means to cause said car to travel at one of said speeds, means operable by movement of said car in said one direction within a lesser distance of said belindarjY for also actuatii'ig said control means to cause said car to travel at said one speed, and means operable by movement of said car in the opposite direction within a predetermined distance of said boundary for actuating said control means to cause said car to operate at another of said speeds.

2. In a control system for elevators, an elevator car operable in a hatchway past a plurality of floors, motive means for said car, means for controlling said motive means to cause said car to run at a plurality of different speeds, means defining a plurality of zones of operation for said ear, each zone including a. plurality of adjacent floors, said Zone-defining means including means operable by movement of said car in one direction within one predetermined distance of the boundary between two of said zones for actuating said control means to cause said car to travel at one of said speeds, means operable by movement of said car in said one direction within a lesser distance of said boundary for also actuating said control means to cause said car to run at said one speed, and means operable by movement of said car in the opposite direction within a predetermined distance ot said boundary for actuating said control means to cause said car to operate at an increased speed.

3. In a control system :tor elevators, an elevator car operable in a hatchway past a plurality of floors, motive means for said car, means for controlling said motive means to cause said car to run at a pluralityv of di'llerent speeds, means defining a plurality of zones of operation for said car, each Zone including a plurality of adjacent floors, said Zone-defining means including a switch for actuating said control means to cause said car to operate at one of said speeds, and means for actuating said switch when said car traveling in one direction passes one point a predetermined distance in advance ot the boundary between two of said zones and for also actuating said switch when said car passes another point a lesser distance in advance of the boundary of said zone, and a second switch operable by movement et s id car in the other direction past a point said boundary for actuating` said control means to cause said car to operate an increased speed.

4. In a control system for elevators, elevator car operable in a hatchway past plurality o1c floors, motive means for said car, means lfor controlling said motive means to cause said car to run at a plurality oit diilerent speeds, means defining a plurality ol1 zones of operation for said car, each Zone including al plurality of adjacent floors, said Zone-defining means including means operable by movement of said car in one direction to al position adjacent to the boundary of two of said zones for actuating said control means to cause said car to operate at one oi said peeds, means operable by iii-oven'icnt of said car in the other direction to a position adjacent to said boundary for actuating control means to cause said car to operate at the greater of said speeds and auxiliary means operable by movement ot said car in said one direction to a point closer to said boundary than said first named point tor actuating said control means to cause said car to operate at said lesser speed.

5. In a control system for elevators, the' combination with an elevator operable over a predetermined path between a plurality oic floors, a motor for said elevator operable at different speeds, means defining zones of operation along said path comprising magnetizable plates located adjacent the junction of said Zones, and means, including relays on said elevator, to cooperate with said plates when the elevator approaches the boundary of a Zone for controlling the motor to determine the speed thereof within said Zone of an auxiliary magnetizable plate adjacent said junction to cooperate with one of said relays to ensure proper speed in the associated zone..

6. In a control system for elevators, the combination with an elevator operable over a predetermined path through a plurality ot' Zones, a motor for said elevator selectively operable at a normally high speed and at an abnormally high speed through the respective Zones, a plurality oi. magnetizable plates located adjacent the junction of said zones, and means, including a plurality of relays on said elevator, to cooperate with said plates when the elevator approaches the boundary of a Zone for controlli-ng the motor to change from one to the other of its speeds, of an auxiliary magnetizable plate also adjacent said junction to cooperate with one oli said relays to control the motor to prevent operation at abnormally high speed in the Zone associated with said relay.

7. In a control system for elevators, the i' in with :in elevator operable over a pl ..1ality of `zones, a motor adapted to operate said elevator at different speeds in the respective Zones, a plurality of magnetizable -lates located adjacent the junction of two Zones and means. including` a plurality of electromagnetic relays on said elevator, to cooperate with said plates when the elevator approaches the junction` of said zones for controlling the motor to change from one to the other of its speeds, of an auxiliary magnetizable plate also adjacent the junction of said Zones to cooperate with one of said rel lays to cause the motor-controlling means to ensure a proper motor speed in the Zone associated with said relay.

S. In a control system for elevators, the combination with an elevator operable over a plurality of zones,a motor adapted to operate said elevator at a normal high speed in one or" said Zones and at an abnormally high speed in the other of said Zones, a plurality of magnetizable plates corresponding in number to the Zones, one of said plates being located in a Zone adjacent to the junction thereof, and means, including a plurality of electromagnetic relays on said elevator, for selectively cooperating with said plates for controlling the motor to change from one to another oi' its speeds when moving from one to another of said Zones, of an auxiliary magnetizable plate located in one of said zones to cooperate with one of said relays to so control the motor as to ensure Operation thereof at the normal high speed in the Zone associated with that relay.

9. In the control system for elevators, the combination with an elevator operable at a normal high speed over a local Zone and at an abnormal high speed over an express zone, an elevator motor adapted to operate at corresponding speeds, a magnetizable plate associated with each of said zones and located close to the junction thereof, and means, including a pair of relays on said elevator, to cooperate selectively with said plates for controlling the motor to change from normal high speed l in the local zone to abnormal high speed in the express zone and vice versa, of an auxiliary magnetizable plate spaced from the other plates to cooperate with one of said relays to control the motor to prevent operation thereof at abnormally high speed in the local m zone.

l0. In a control system for an elevator car operable over a predetermined path past a plurality of floors, a multi-speed motor for driving said car, means defining zones of operation along said path in each of which zones the speed of said car is limited to a predetermined speed different from the speed to which the car is limited in an adjacent Zone, said means including a plurality of switches 2 each corresponding to a zone and operable to change the speed of said car prior to entry of l the car into the corresponding zone, means for selectively operating said switches in accordance With the position of the car in the n said path, and means independent of said selectively operating means, for effecting the operation of a said switch to prevent the entry of the car into a Zone corresponding to that switch at a speed in excess of the predetermined speed to which the car is limited in that zone.

In testimony whereof, I have hereunto subscribed my name this 23rd day of May, 1929.

HAROLD W. WILLIAMS. 

